A great move by a tactical magician in his element.
9... c8e6 Considering what happens in the game, maybe it was safer for Black to play either 9...f5 or 9...Ng6, with a good position in both cases. 10. d2e4  10... b8d7  11. g3g4 Otherwise Black simply plays f7-f5. 11... e7g6 This leads to a very dangerous position for Black after Firouzja's next move.